Feasibility of quantitative diffusion imaging of the heart in post-mortem MR

ObjectiveThe aim of this work was to investigate the feasibility of quantitative diffusion imaging of the heart in a post-mortem setting and compare these results to standard T2-weighted imaging as well as to traditional autopsy and histological analysis.Materials and methodsTwo human cadavers underwent post-mortem magnetic resonance (PMMR) imaging of the heart, autopsy and histological analysis of the myocardium. Diffusion weighted double-echo steady-state data with direction sensitivity in three orthogonal directions have been acquired from which the mean-diffusivity has been estimated. In addition, T2-weighted data have been acquired. PMMR images were compared to autopsy and histology.ResultsDirection dependent diffusivity-maps revealed a strong dependency on the orientation of the myocardial fibers; the resulting mean-diffusivity-maps are independent of the fiber direction. Findings in the mean-diffusivity-maps revealed good correspondence to findings in T2-weighted images as well as to the autopsy and histology findings. Long axis reconstructions of the mean-diffusivity-maps gave further insight into the extent of an acute infarction of one case.ConclusionsThis study shows that quantitative diffusion imaging of the heart is applicable in a post-mortem setting to identify scar-tissue as well as acute infarction in the myocardium. Three-dimensional isotropic diffusivity-mapping additionally allows for the reconstruction of slices in any orientation for optimal visualization of the results.